DESCRIPTION: Evoked otoacoustic emissions (OAE) are produced by active processes in the inner ear by interactions with external tones, and provide important data for modeling the mechanisms of hearing. The existence of spontaneous otoacoustic emissions (SOAE), while themselves apparently having no direct role in hearing, pose a problem that any realistic model of the cochlea must account for. A model of the auditory periphery is proposed to account for the large body of data on OAEs, which will have a profound impact on the hearing research carried out by this Purdue group. The model connects apparently disparate phenomenon in a mathematically rigorous fashion, and thus guides the scope of specific experiments and suggests new experiments. The models have significance for the clinical use of SOAEs and evoked OAEs in hearing assessment, particularly for distortion product OAEs, since the question of understanding the underlying mechanisms has an impact on how results should be interpreted clinically. It is expected that the model will play an important role on the group's future research in clinical applications of evoked OAEs.